Thoracic Extension of the Spine and the Serve

Chas Tennis

G.O.A.T.
WARNING - How your spine is used during the serve can risk injury. Many backs are not capable of much Thoracic Extension. ?


The extension of the thoracic spine is brief and when it occurs can be seen in videos of high level servers.


Thoracic Extension is mid-back, different than the lower back.

There have been posts on Thoracic Extension. TE is probably used in a similar way for the baseball pitch.
 
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heninfan99

Talk Tennis Guru
such thoracic and neck flexibility is more a factor on the kick serve but the good news is most young athletes can bend in this way.
 

Raul_SJ

G.O.A.T.
such thoracic and neck flexibility is more a factor on the kick serve but the good news is most young athletes can bend in this way.
I recall that there has been discussion here on lower back bend on the kick serve and the consensus was that there is relatively little lower back bend on the kick serve (not twist serve)...

SystemicAnomaly said:
Should not arch the back very much at all. If you bend your knees sufficiently, you can lay your upper body back with only moderate back arch. One key to this is let your heels come off the ground when you bend your knees.
Also, I am not clear on the difference between lower back extension and mid-back (thoracic) extension. The guy in the pic looks like he his severely bending his lower back, far more than what occurs on a kick serve? If so, why is Jeff making an issue of this?... And how much is thoracic extension movement independent of lower back extension?
:unsure:

 

J011yroger

Talk Tennis Guru
Is that a kick serve? Or flat serve?
And I am guessing the pic is mainly mid-back (thoracic) extension rather than lower back extension?
It's a 2nd serve, I try to keep my lower back straight and point my chest at the ball on all serves.

J
 

heninfan99

Talk Tennis Guru
I recall that there has been discussion here on lower back bend on the kick serve and the consensus was that there is relatively little lower back bend on the kick serve (not twist serve)...
Also, I am not clear on the difference between lower back extension and mid-back (thoracic) extension. The guy in the pic looks like he his severely bending his lower back, far more than what occurs on a kick serve? If so, why is Jeff making an issue of this?... And how much is thoracic extension movement independent of lower back extension?
:unsure:
47:35 in.
 

Raul_SJ

G.O.A.T.
It's a 2nd serve, I try to keep my lower back straight and point my chest at the ball on all serves.

J
That sounds safe. Less risk for lower back strain because there is actually little lower back extension on the kick serve; mostly thoracic extension.
Jeff must be using the below pic just for screening purposes, not to suggest that this degree of lower back bend actually occurs on a kick serve.

 

Chas Tennis

G.O.A.T.
................................
..........The guy in the pic looks like he his severely bending his lower back, far more than what occurs on a kick serve? If so, why is Jeff making an issue of this?......
That does seem to involve more the lower back. ?
 

Raul_SJ

G.O.A.T.
That does seem to involve more the lower back. ?
I think Jeff is using the test as a screening tool to measure general flexibility. Not to imply that this level of lower back arch, or anything close to it, actually occurs on a serve.
But it still raises the question of the validity of using the the test result to predict serve problems.
And presumably many who fail the flexibility test would not preclude them from serving effectively as one can hit kick serve very effectively employing very little lower back arch.

The thoracic extension is far more critical. Would prefer a flexibilty test that measures more of the thoracic extension.
 
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Digital Atheist

Professional
I find these technical discussions interesting from a knowledge point of view, but I know little to nothing about how this information is translated into the teaching of real world serves. In this case it obviously makes sense from an injury prevention perspective and that's something everyone should be aware of.

I always thought tilt (spine extension or whatever it's called) without a big back arch was a good thing, as demonstrated by Sampras, Federer, Safin etc. Even Wawrinka, who is often criticised for a small knee bend and a high elbow, has this feature. It is interesting to observe that a large number of WTA servers - including some of the best - have very little tilt at the trophy position, but are still able to utilise what I'm now assuming is thoracic extension (through leg drive??) to help generate power when launching at the ball (Ka. Pliskova, Osaka, Serena etc).













Edit: Maybe I'm mistaken about Serena, and she might actually have a small tilt (boobs and butt may have misled me optically on that one). But Pliskova's trophy isn't what Salzy would advocate, also upright, and Osaka's torso is very upright with a Wawrinka-like high elbow but she still hits bombs.

So I am wondering how spinal tilt affects thoracic extension.

I don't get back, shoulder, or arm pain (I'll be 50 in a week), but I'm now wondering if I tilt too much, even on first serves. This is a flat serve down the T.



Is this bad or wrong? I taught myself which could be part of the problem, but I never thought about any of this stuff when I was trying to "figure it out".
 
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J011yroger

Talk Tennis Guru
I find these technical discussions interesting from a knowledge point of view, but I know little to nothing about how this information is translated into the teaching of real world serves. In this case it obviously makes sense from an injury prevention perspective and that's something everyone should be aware of.

I always thought tilt (spine extension or whatever it's called) without a big back arch was a good thing, as demonstrated by Sampras, Federer, Safin etc. Even Wawrinka, who is often criticised for a small knee bend and a high elbow, has this feature. It is interesting to observe that a large number of WTA servers - including some of the best - have very little tilt at the trophy position, but are still able to utilise what I'm now assuming is thoracic extension (through leg drive??) to help generate power when launching at the ball (Ka. Pliskova, Serena etc).

Edit: Images of some of the above servers to come soon.

I don't get back, shoulder, or arm pain (I'll be 50 in a week), but I'm now wondering if I tilt too much, even on first serves. This is a flat serve down the T.



Is this bad or wrong? I taught myself which could be part of the problem, but I never thought about any of this stuff when I was trying to "figure it out".


J
 

Digital Atheist

Professional
Thanks, I'm guessing you're suggesting I do have too much tilt to the left.

If you're ever* in the mood, feel free to post other criticisms or possible improvements here (video embedded):
https://tt.tennis-warehouse.com/index.php?threads/serve-toss-and-tossing-arm-positioning.654481/#post-13828568

When I was working on my serve, I ended up modelling Safin and Serena; partly because of Serena's take back, that and they both use a similar pinpoint stance to me.



He does the same (even more exaggerated due to camera angle possibly) on the deuce court. But maybe this isn't optimal, hence my question.
 
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Raul_SJ

G.O.A.T.
Lumbar spine (lower back) normal ROM: 30 degrees extension
Thoracic (upper back) normal ROM: 25 degrees extension

The idea on the serve is to try to maintain more of a straight lower back while emphasizing thorax extension.



 
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J011yroger

Talk Tennis Guru
Thanks, I'm guessing you're suggesting I do have too much tilt to the left.

If you're ever* in the mood, feel free to post other criticisms or possible improvements here (video embedded):
https://tt.tennis-warehouse.com/index.php?threads/serve-toss-and-tossing-arm-positioning.654481/#post-13828568

When I was working on my serve, I ended up modelling Safin and Serena; partly because of Serena's take back, that and they both use a similar pinpoint stance to me.



He does the same (even more exaggerated due to camera angle possibly) on the deuce court. But maybe this isn't optimal, hence my question.
It's not so much the tilt as your weight distribution, you are off balance because too much of your weight is behind you.

1. Your body will want to keep your tossing arm down to provide counter balance because if you brought it up all the way for a good front side stretch you would fall over backwards.

2. It puts too much strain on your body and forces an inconsistent and jerky motion,

3. You will fall to the left in your finish to catch your balance.

J
 

Chas Tennis

G.O.A.T.
I have often seen advice to 'point your chest up' during the serve with nothing more said on timing or purpose.

I think that I've seen timing of Thoracic Extension around the time of the acceleration from jumping. But I have not studied the details or variations.

Maybe some player have a straighter back. ? Can't find a good slow motion of Greg Rusedski.

---------------------------------------------------------------------------------------
Anatomy


Florida Medical Clinic


Attachments of lat. (These pictures show some variations.)

Yoganatomy
 
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J011yroger

Talk Tennis Guru
I have often seen advice to 'point your chest up' during the serve with nothing more said on timing or purpose.

I think that I've seen timing of Thoracic Extension around the time of the acceleration from jumping. But I have not studied the details or variations.

Maybe some player have a straighter back. ? Can't find a good slow motion of Greg Rusedski.

---------------------------------------------------------------------------------------
Anatomy


Florida Medical Clinic


Attachments of lat. (These pictures show some variations.)

Yoganatomy
Wait, you really don't know why you point your chest up?

J
 

Digital Atheist

Professional
It's not so much the tilt as your weight distribution, you are off balance because too much of your weight is behind you.

1. Your body will want to keep your tossing arm down to provide counter balance because if you brought it up all the way for a good front side stretch you would fall over backwards.

2. It puts too much strain on your body and forces an inconsistent and jerky motion,

3. You will fall to the left in your finish to catch your balance.

J
That's useful information, thanks. More to work on!
 

Chas Tennis

G.O.A.T.
Wait, you really don't know why you point your chest up?

J
I don't know and have not found tennis research on the function of Thoracic Extension.

Take a look at the anatomy of the lat, particularly the origin and the insertion in post #15. What are the effects of Thoracic Extension?

Closely related threads and posts below.

Raising the hitting shoulder and its effects.
Serve - Is raising the hitting shoulder the last big stretch?

Background
- My interpretation of some biomechanical research results on the serve-

During the service motion, first, the tossing shoulder is up and the hitting shoulder is down. Then the hitting shoulder is very rapidly moved high using trunk lateral flexion. Last, the final racket head speed is increased to ball impact using mostly internal shoulder rotation. Internal shoulder rotation contributes the most to racket head speed.

The internal shoulder rotators are pre-stretched by the leg thrust. The stretch occurs because the upper arm is at about 90° to the body and the racket and forearm are at about 90° to the upper arm when the legs thrust up and carry along the shoulder. This externally rotates the shoulder stretching the internal shoulder rotator muscles. The internal shoulder rotator muscles are the lat (Latissimus Dorsi), pec (Pectoralis Major), Teres Major and some others. The largest muscle connected to the arm is the lat, the second largest is the pec. Both insert on the front of the upper arm at the same location and internally rotate the shoulder by pulling on the humerus at that insertion point.

The question is what part does raising the hitting shoulder play in farther stretching the lat or in maintaining the stretch?

Apparently it is well known that raising the shoulder can increase the lat stretch.

From the Manual of Structural Kinesiology, C. Thompson, R. Floyd, 15th ed., page 89:

paraphrasing

The stretch (of the lat) may be increased ................by then laterally flexing and rotating the trunk to the opposite side.

(This is a great basic reference. It is a popular college text and the latest edition is $75 while the recent editions like the 15th are just $10 or so.)

Lateral trunk flexion is just the side bend that puts the hitting shoulder up. Rotation of the trunk is just the trunk turn that is used for serving. Both of these lat stretches can easily be felt by just holding the upper arm at 90° to the body and rotating the forearm up and back as in the service motion to give the internal rotators some stretch. When stretched in that way, laterally(side) bend the trunk, feel the lat stretch. Also rotate the trunk and feel the lat stretch.

In Knudson's book, Biomechanical Principles of Tennis Technique, I think he discusses the speed of stretched muscles as more rapid.

Does this late trunk flexion and rotation play an important part for the serve by final stretching of the lat for added racket head speed?
I am trying to identify all stretch details of the lat associated with motions of the serve.

Here is some more detail. I'd be interested in how the points that you mentioned correspond to these points.

This description from the Manual of Structural Kinesiology is not for the serve but in general identifies some motions and their effect on stretching the lat. These motions are all present in the serve, in fact, the description reads like part of the service motion.

"The latissimus dorsi is stretched with the teres major when the shoulder is externally rotated while in a 90-degree abducted position. This stretch may be accentuated further by abducting the shoulder fully while maintaining external rotation and then laterally flexing the trunk and rotating the trunk to the opposite side."

Breakdown-

1) "The latissimus dorsi is stretched with the teres major when the shoulder is externally rotated while in a 90-degree abducted position."

The corresponding parts of the service motion are 1) the upper arm aligned with the line between the shoulders ("90-degree abducted position"). 2) External rotation occurs from the shoulder external rotators and also because the forearm and racket are bent, say, at very roughly 90 degrees to the upper arm when the legs thrust up. The inertia of the forearm and racket stretch the internal shoulder rotators.

2) ......"This stretch may be accentuated further by abducting the shoulder fully while maintaining external rotation..."

There is no corresponding part of the serve because it does not occur in proper technique since farther abducting the shoulder results in more risk of impingement. (McLennan & Ellenbecker videos on shoulder injury) The upper arm should remain in a rough line with line between the shoulders.

3) "...while fully maintaining the external rotation and then laterally flexing the trunk ......................"

The corresponding part of the serve is the lateral trunk flexion that brings down the tossing shoulder and raises the hitting shoulder. Probably starting, as often recommended, with the front hip bowed forward allows more range of trunk flexion and therefore greater lat stretch. ? I have not seen another clear explanation as to why having the hip forward would help the serve.

4) "while fully maintaining the external rotation and then .........rotating the trunk to the opposite side."

The corresponding part of the serve would be 'body turn' (sometimes loosely called 'shoulder turn.') Rotating the trunk can stretch the lat. Also, pointing the chest up, stretching the lat, and then rotating the trunk forward can farther stretch the lat. This may account for the 'chest up' recommendation often heard. Otherwise, what is the reason?

I have sort of a stretch-then release viewpoint where the lat muscle is first stretched for internal shoulder rotation and then released. Maybe some of these stretching motions could also drive the serve very fast more directly. ?

Ways to stretch muscles for the Stretch Shorten Cycle.
One example of an additional way to stretch muscles (not the abdominal muscles in this illustration)-
The method can be applied using other body parts.

Hint - The muscle involved will be stretched more. The lat.....

See posts by dominick1985 on Thoracic Extension.

Back bending is likely to be too stressful for the backs of many/most players.
I would speculate that Thoracic Extension is not done directly for speed of the uppermost body but for its possible effect of changing the distance between the origin and insertion of the lat. ? (See two joint muscle) Understanding what is going on in high level serve biomechanics is the goal of the thread.

This is in addition to the ESR-ISR motions of the serve that also stretch the ISR muscles. Thoracic Extension could be used to stretch the lat or move the shoulder joint directly as the TE occurs, or for a mixture of both purposes. ??
 
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Raul_SJ

G.O.A.T.


We're gonna talk about thoracic mobility today. What the heck is that word? Thoracic it has to do with the mid-back. So many players focus on the lower back and they even have low back pain. And the reason that you're not serving well, one big reason is probably because you lack thoracic mobility.

We're gonna go over some drills today loosen up this area. When I analyze serves I see a lot of players get into a position like a flat, yep really flat and if you want to have a great kick serve or topspin serve you've got to develop your thoracic so your thoracic spine get some mobility. So when I get here we're looking for that extension right here all overhead athletes if you're not able to extend there's no power coming from that shoulder right and so if you also struggle with your racket drop that there's a probably a good chance that you're not able to move from the mid-back which lacks the the ability to rotate from the shoulder.

We are going to show some very simple exercises that you can use with a foam roller to improve that thoracic mobility so that you can hit better serves and get more power into your ground strokes. I want you to do go ahead lie on your back for me we're gonna set this right in the middle right in the middle of your back. I want you to just roll back and forth and let your let your body just drape over that foam just feel that that chest open up back expands. You're just loosen up that spine putting it into an extension.... I have some athletes they'll get down here that's killing them; there's no mobility whatsoever in the spine.

 

Raul_SJ

G.O.A.T.
Is the purpose of pointing chest up to facilitate shoulder-over-shoulder / cart wheel rotation around the spine axis?
"Chest up" is more critical on kick serves where toss is more toward's 11 o'clock. Only way to swing up for topspin is having the chest face up.

Not sure if "chest up and straighten" (crunch) particularly facilitates shoulder-over-shoulder (cartwheeling) motion. I tend to view the two as 2 independent motions.
In other words, is it possible to crunch and cartwheel simultaneously? I think not. :unsure:



According to Jim McLennan video, there are 3 main actions the shoulder girdle can do:​
1) Somersaulting. Arch the back and straighten. AKA as "the crunch".​
2) Cartwheeling.​
3) Rotation along the long axis (the spine).​
Jim says you want to delay that #3 rotation and focus on staying sideways, #2 cartwheeling. He is now placing all his coaching emphasis on the cartwheeling. If you notice Federer at contact, he will be sideways, and his rotation along the long axis is at the last moment.​
 
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J011yroger

Talk Tennis Guru
I do this every time I practice my serve, sometimes I do a quick sweep in front of the baseline to see better.

I serve platform so it's a little bit different but the red line is the toe of my back (right) foot the blue circle is where I push off with my back foot and the yellow circle is where I land with that back foot.

Obviously my left foot lands first just inside the baseline but where the right foot lands shows the direction of my momentum and you want that momentum straight ahead or to the right.

So many rec players fall off to the left.



J
 

J011yroger

Talk Tennis Guru
"Chest up" is more critical on kick serves where toss is more toward's 11 o'clock. Only way to swing up for topspin is having the chest face up.

Not sure if "chest up and straighten" (crunch) particularly facilitates shoulder-over-shoulder (cartwheeling) motion. I tend to view the two as 2 independent motions.
In other words, is it possible to crunch and cartwheel simultaneously? I think not. :unsure:



According to Jim McLennan video, there are 3 main actions the shoulder girdle can do:​
1) Somersaulting. Arch the back and straighten. AKA as "the crunch".​
2) Cartwheeling.​
3) Rotation along the long axis (the spine).​
Jim says you want to delay that #3 rotation and focus on staying sideways, #2 cartwheeling. He is now placing all his coaching emphasis on the cartwheeling. If you notice Federer at contact, he will be sideways, and his rotation along the long axis is at the last moment.​
Ball has topspin, chest isn't facing up.


J
 

Chas Tennis

G.O.A.T.
Look at the Thoracic Extension and Thoracic Flexion motion from 17 to 19 seconds. (1 second of 30 fps playback time equals 1/8 second of real time with 240 fps recording.)
Single frame on Vimeo, hold down the SHIFT KEY and use the ARROW KEYS. Use full frame.

The spine bending Thoracic Extension motion is fast and occurs as the legs thrust in contact with the ground (and after?). In the above video, the time from the spine being about at maximum Thoracic Extension to the time of bending back with Thoracic Flexion to near straight again, looks like about 15 frames or 0.06 second. (240 fps) The total time to bend the back into TE and straighten it again is about 37 frames or 0.15 second. (I remember when I heard that 'the chest should face up', I would try to do that very early in the service motion with no idea of the timing shown in the above video.)

The black line of his shorts waist band is an indicator that his pelvis is rising from the leg thrust and jump. The double lines on his shirt help in estimating TE. The main acceleration will be as the legs thrust while in contact with the ground. Thoracic Extension (and Lumbar?) occurs instead of keeping the spine straighter and more upright above the pelvis - more back bending and less acceleration of the uppermost body mass up.

Raonic watches the ball approaching impact and appears to break off watching just before impact, I believe to avoid neck stress. His face faces up at maximum angle when his Thoracic Extension is maximum. As he goes to Thoracic Flexion he breaks off looking at the ball and his face faces to forward. Some servers look at the ball through impact, but not the majority which are more like Raonic.

This is intended as information on what a high level ATP server is doing during one part of the serve. Other details are not known.
 
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Chas Tennis

G.O.A.T.
Similar biomechanics for the baseball pitch.

The Kinetic Chain in Overhand Pitching
Its Potential Role for Performance Enhancement and Injury Prevention
Shane T. Seroyer, MD,* Shane J. Nho, MD, Bernard R. Bach, MD, Charles A. Bush-Joseph, MD, Gregory P. Nicholson, MD, and Anthony A. Romeo, MD




The frame marked "h" (side view) appears to show some Thoracic Extension (TE) and that TE is gone for the next frame "i". The pitcher is accelerating forward between frames f and h. Does he get that lag of the uppermost body from the inertia of the uppermost body and Thoracic Extension? When he re-straightens his back by frame f, the distance between the origin and insertion of the lat has been lengthened. Forces from that lengthening could cause the shoulder joint to bring the arm forward (forward extension?) or for ISR, or a combination of both. The lat goes under the shoulder joint so when the lat pulls it brings the arm forward or rotates the upper arm with ISR.

This seems similar to the tennis serve in the function of Thoracic Extension/Flexion.
 

J011yroger

Talk Tennis Guru
Similar biomechanics for the baseball pitch.

The Kinetic Chain in Overhand Pitching
Its Potential Role for Performance Enhancement and Injury Prevention
Shane T. Seroyer, MD,* Shane J. Nho, MD, Bernard R. Bach, MD, Charles A. Bush-Joseph, MD, Gregory P. Nicholson, MD, and Anthony A. Romeo, MD




The frame marked "h" (side view) appears to show some Thoracic Extension (TE) and that TE is gone for the next frame "i". The pitcher is accelerating forward between frames f and h. Does he get that lag of the uppermost body from the inertia of the uppermost body and Thoracic Extension? When he re-straightens his back by frame f, the distance between the origin and insertion of the lat has been lengthened. Forces from that lengthening could cause the shoulder joint to bring the arm forward (forward extension?) or for ISR, or a combination of both. The lat goes under the shoulder joint so when the lat pulls it brings the arm forward or rotates the upper arm with ISR.

This seems similar to the tennis serve in the function of Thoracic Extension/Flexion.
Why don't you look at someone throwing a ball in from the outfield.

J
 

Raul_SJ

G.O.A.T.
Pat Dougherty video with some interesting comments about 'chest up'.
Pat suggests that "chest up" angle reduces risk of impingement. Not sure I agree.

Ellenbecker and Jim McLennan video describes dropping the front non-hitting shoulder to maintain safe hitting shoulder abduction angle. But that is not contingent on chest up style. When Jim demonstrates, he does not have chest up. More of a shoulder-over-shoulder cartwheel type motion.
Impingement is avoided by dropping the front shoulder -- regardless of whether or not player is using a chest up style..
 
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Chas Tennis

G.O.A.T.
There are probably exercises developed for tennis. In the meantime, here are some general exercises and stretches.

Posture and head forward.

Thoracic exercises.

Eric Cressey on Thoracic conditioning for throwers.

FYI Jeff Salzenstein comments on Eric Cressey.
 
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Chas Tennis

G.O.A.T.
................................................. Only way to swing up for topspin is having the chest face up.
.....................................................................................................
Words can over simplify the 3D nature of the serve. For the kick serve, 1) the forward tilt of the spine, 2) how the chest is facing and 3) where the sides of the chest are, aren't well described by saying "chest face up". Also, words need the time of the stroke to convey information. When does the "chest face up" occur, at impact? Do you mean at an earlier time? There must be frames from videos that correspond to what is described by the words and that should always be shown.

How is the chest facing in this video? Up? To the side? Is it "staying" some way? For how long? At what time is the chest oriented some way? The word "stay" means "remain in the same state or position" or "remain in the same place". What words convey that one side of the chest is very low or and one side is very high. When the word descriptions are used in an undefined way then readers pick their own interpretations and that becomes part of their understanding. I have used these word descriptions for decades and when I looked at high speed videos most of them were not true.
For single frame on Vimeo, hold down the SHIFT KEY and use the ARROW KEYS.

If the chest faces up for 1/10 second during a top spin service motion of 1 second and then faces other directions for 9/10s second, how is that described by "chest faces up".

In posts, I have disagreed many times, with 'the chest faces the side on the kick serve'. But I said the chest "faces more to the side" as some other videos show. But when I look at that Stosur serve her chest seems to 'face the side' at impact. But the chest also is very tilted and she moves to that position and holds it for a limited time. To some degree I have fooled myself by using words and not basing my own descriptions only on high speed videos. When I think of 'facing the side' I'm upright and simply turn to the side with no thought of the extreme body tilt that Stosur shows above. There is a great deal of information in high speed videos. There is not enough information to describe tennis strokes in a few easy to remember words.

Words are great for describing what you are looking at in high speed videos.
 
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J011yroger

Talk Tennis Guru
Words can over simplify the 3D nature of the serve. For the kick serve, 1) the forward tilt of the spine, 2) how the chest is facing and 3) where the sides of the chest are, aren't well described by saying "chest face up". Also, words need the time of the stroke to convey information. When does the "chest face up" occur, at impact? Do you mean at an earlier time? There must be frames from videos that correspond to what is described by the words and that should always be shown.

How is the chest facing in this video? Up? To the side? Is it "staying" some way? For how long? At what time is the chest oriented some way? The word "stay" means "remain in the same state or position" or "remain in the same place". What words convey that one side of the chest is very low or and one side is very high. When the word descriptions are used in an undefined way then readers pick their own interpretations and that becomes part of their understanding. I have used three word descriptions for decades and when I looked at high speed videos most of them were not true.
For single frame on Vimeo, hold down the SHIFT KEY and use the ARROW KEYS.

If the chest faces up for 1/10 second during a top spin service motion of 1 second and then faces other directions for 9/10s second, how is that described by "chest faces up".

In posts, I have disagreed many times, with 'the chest faces the side on the kick serve'. But I said the chest "faces more to the side" as some other videos show. But when I look at that Stosur serve her chest seems to 'face the side' at impact. But the chest also is very tilted and she moves to that position and holds it for a limited time. To some degree I have fooled myself by using words and not basing my own descriptions only on high speed videos. When I think of 'facing the side' I'm upright and simply turn to the side with no thought of the extreme body tilt that Stosur shows above. There is a great deal of information in high speed videos. There is not enough information to describe tennis strokes in a few easy to remember words.

Words are great for describing what you are looking at in high speed videos.
Miraculously they all learned how to do it with good coaching and minimal high speed video analysis.

J
 

BlueB

Legend
I recall that there has been discussion here on lower back bend on the kick serve and the consensus was that there is relatively little lower back bend on the kick serve (not twist serve)...



Also, I am not clear on the difference between lower back extension and mid-back (thoracic) extension. The guy in the pic looks like he his severely bending his lower back, far more than what occurs on a kick serve? If so, why is Jeff making an issue of this?... And how much is thoracic extension movement independent of lower back extension?
:unsure:

Good part of the arch, shown in the pic, comes from the hip joints.

Sent from my SM-G965W using Tapatalk
 

Chas Tennis

G.O.A.T.
Miraculously they all learned how to do it with good coaching and minimal high speed video analysis.

J
"They all" didn't learn how to do it.

But obviously motivated athletes and knowledgeable coaches working seriously together is the most successful approach in 2019. I assume ATP top 100 train often with feedback from high speed video but I have no stats.

I just saw a stat on a Tennis Channel match broadcast. There are 87,000,000 tennis players world wide, ITF estimate. What percent can hit a high level kick serve?
 
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J011yroger

Talk Tennis Guru
"They all" didn't learn how to do it.

But obviously motivated athletes and knowledgeable coaches working seriously together is the most successful approach in 2019. I assume ATP top 100 train with feedback from high speed video but I have no stats.

I just saw a stat on a Tennis Channel match broadcast. There are 87,000,000 tennis players world wide. What percent can hit a high level kick serve?
They all meaning everyone you are posting video of.

Most decent 12 year olds can hit a kick serve, and it's not very common to use high speed comparison to ATP players with 12 year olds.

J
 

Chas Tennis

G.O.A.T.
Raonic does Thoracic Extension + Lumbar to maximum and then Throacic Flexion + Lumbar back to neutral in about 0.15 second. A good new fact on timing to take away from this thread.
 

Chas Tennis

G.O.A.T.
...................................... it's not very common to use high speed comparison to ATP players with 12 year olds.
Kinovea is a great tool for comparisons and it is not too hard to use. It has side-by-side comparisons and even has a countdown mode so that two strokes can be shown so that impact occurs in the same side-by-side frame of each video. Seeing differences is very direct at any time of the stroke.

But 12 year old boys have not developed enough yet to do everything that ATP players do. There is some developmental information in Technique Development for Tennis Stroke Production. 2009, Elliott, Reid, and Crespo. Also, there are research publications. I just saw an Elliott video where he was teaching coaches, will try to find.

If one 12 year old had a great kick serve and another was below average, you might say that one is 'very talented'. And that might be true. But it might be that one's racket meets the ball with a different racket face angle than the other's, easy to see in high speed videos.........
 
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J011yroger

Talk Tennis Guru
Kinovea is a great tool for comparisons and it is not too hard to use. It has side-by-side comparisons and even has a countdown mode so that two strokes can be shown so that impact occurs in the same side-by-side frame of each video. Seeing differences is very direct at any time of the stroke.

But 12 year old boys have not developed enough yet to do everything that ATP players do. There is some developmental information in Technique Development for Tennis Stroke Production. 2009, Elliott, Reid, and Crespo. Also, there are research publications. I just saw an Elliott video where he was teaching coaches, will try to find.

If one 12 year old had a great kick serve and another was below average, you might say that one is 'very talented'. And that might be true. But it might be that one's racket meets the ball with a different racket face angle than the other's, easy to see in high speed videos.........
You ever tell a 12 year old to meet the ball with a different racquet face angle?

J
 

Chas Tennis

G.O.A.T.
You ever tell a 12 year old to meet the ball with a different racquet face angle?......
No.

The angle on the face is too complicated.

For single frame on Youtube use the "." and "," keys.

But on one particular camera view - of one angle, at one instant of time like just before impact, things are simplified. See Toly's "13 degrees" frame at 34 sec, where he measures how closed the racket face is just after impact.

If that closed angle is true, then maybe the 12 year old should become aware of it. ? Since the racket may be too fast for the coach to see, what feedback does the coach have for this racket angle issue?
 
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J011yroger

Talk Tennis Guru
No.

The angle on the face is too complicated.

For single frame on Youtube use the "." and "," keys.

But on one particular camera view - of one angle, at one instant of time like just before impact, things are simplified. See Toly's "13 degrees" frame at 34 sec, where he measures how closed the racket face is just after impact.

If that closed angle is true, then maybe the 12 year old should become aware of it. ? Since the racket may be too fast for the coach to see, what feedback does the coach have for this racket angle issue?
You can tell by what the ball does and the sound of it as well as watching the serve.

And there are a number of drills to get the kid to make the required adjustments.

J
 
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